RefractometryRefractometry
is a technique that measures how light is refracted when it passes
through a given substance, in this case, an unknown compound. The amount
by which the light is refracted determines the refractive index. Refractive
index can be used to identify an unknown liquid compound, or it can
be used as a means of measuring the purity of a liquid compound by
comparing it to literature values. The closer the refractive index
is to the literature values, the purer the sample. Refractive index
is defined as the ratio of the velocity of light in air to the velocity
of light in the medium being measured:
nD = [V air]/(V liquid)